Veterinary diagnostic equipments ECG.ppt

Electrocardiogram

1. ECG -ELECTROCARDIOGRAM
Veterinary Diagnostic Equipments

2. ECG
Recording the electrical activity of the heart
from electrodes placed on the skin in specific
locations

3. Electrical activity of the
heart
SA node --> atrial muscle --> AV node -->
bundle of His --> Left and Right Bundle
Branches --> ventricular muscle

4. Recording of the ECG
ECG's utilize 12 leads
6 limb leads
6 precordial leads
Limb leadsare: I, II, III, aVR, aVL, and aVF
Precordial leadsare: V1, V2, V3, V4, V5, and V6

5. Connecting Lead wires

6. Leadwirescolor coding
standards
Yellow –Left front limb
Red –Right front limb
Black –Right back limb
Green –Left Back limb
White –Chest lead

7. Leadwires
Fur should be shaved on the connecting point
ECG gel or alcohol is applied on the surface

8. Plane diagram

9. Frontal plane diagram

10. Limb leads

11. Precordialleads
Transverse Section At The 6th Intercostal Space
Showing The Position Of The Horizontal Plane Leads

12. Standards conventions when
reading an ECG
The rate of paper (i.e. of recording of the ECG) is
25 mm/s which results in:
1 mm = 0.04 sec (or each individual block)
5 mm = 0.2 sec (or between 2 dark vertical lines)
The voltage recorded from the leads is also
standardized on the paper where 1 mm = 0.1 mV
(or between each individual block vertically) This
results in:
5 mm = 0.5 mV (or between 2 dark horizontal lines)
10 mm = 1.0 mv(this is how it is usually marked on the
ECG's)

13. ECG paper
Thermal paper is used

14. Elements of the ECG
•P wave
•depolarization of both atria
•PR interval
•atria to venricularconduction time (through His bundle)
•Q wave: first down stroke of the QRS complex.
•R wave: first upward deflection of the QRS complex
•S wave: the first downward deflection occurring after the R wave.
•QT interval
•QRS complex
•the duration of activation and recovery of the ventricular
muscle.
•T wave
•ventricular repolarization

15. ECG artifacts
The waves that arise from sources other than
heart.
Prevent artifacts
Well grounded ECG machine
Placing the patient on rubber mat
Wearing rubber glows by the handlers
Prevent muscle tremor.
Good ECG ECG with mains hum 50HzECG with EMG noise

16. Maintenance of ECG Machines
Daily
Cleaning
Clean off dust with dry cloth and replace dust cover
Visual checks
Check that battery charge indicator, power indicator
and patient cable connector indicators are working
Function checks
Check the calibration of machine before use using
1mV pulse
Check the baseline of the ECG recording is steady
Check the printing is clear

17. Maintenance of ECG Machines
Weekly
Cleaning
Clean the printing head
Visual checks
Check all cables are not bent, knotted or damaged
Replace any damaged electrical plugs, sockets or cables
Check all knobs, switches and indicators are tightly fitted
Function checks
Check the calibration of recordings with ECG simulator
Check battery power can operate the equipment